human impacts on the environment program supplement

Interactive Biology™ Multimedia Courseware

HUMAN IMPACTS ON THE ENVIRONMENTProgram Supplement

Copyright 1999 CyberEd™ Inc.

Human Impacts on the EnvironmentTABLE OF CONTENTS

Outline of subject areas……………………………………………………………… 3

Study Guides(1) Human Impacts: A Brief History………………………………………....…4(2) Environmental Pollution……………………………………………………..5(3) Habitat Destruction, Natural Resource (4) Depletion, and the Loss of Biodiversity……………………………………..9(5) Methods of Conservation……………………………………………………11

Quizzes(1) Human Impacts: A Brief History……………………………………………13(2) Environmental Pollution…………………………………………………......15(3) Habitat Destruction, Natural Resource (4) Depletion, and the Loss of Biodiversity……………………………………..19(5) Methods of Conservation…………………………………………………….21

Comprehensive Exam…………………………………………………………………22

Answer Key…………………………………………………………………………...30

Glossary……………………………………………………………………………….31

Copyright 1999 CyberEd ™ Inc. 2

Human Impacts on the Environment

PROGRAM SUPPLEMENT

The following subject areas are addressed throughout the Interactive Biology MultimediaCourseware program, Human Impacts on the Environment.

• A brief history of human impacts on the environment

• The causes and effects of different types of environmental pollution

• Habitat destruction, natural resource depletion, and loss of biodiversity

• Methods of conservation


Study Guide #1

HUMAN IMPACTS: A BRIEF HISTORY

Every organism impacts the environment in which it lives. Like other organisms, humans drawtheir basic survival needs from the environment. Unfortunately, some human activity has hadadverse impacts on the environment, leading to environmental pollution, habitat destruction,natural resource exploitation, and the loss of biodiversity.

Looking back in time, our predecessors livedsimple hunter-gatherer lifestyles. They hunt-ed animals, gathered fruits and vegetables, andscavenged the prey of other animals. Theylived in small groups and moved in accordancewith changing environmental conditions.Although their impacts on the environmentwere relatively small, hunters and gathererscertainly altered their environment. For exam-ple, they played a significant role in the extinc-tion of several large animals.

New environmental impacts came about a few thousand years ago as people developed simpleagricultural practices. Slash and burnfarming in forested areas; the invention of the plow,which allowed people to farm the rich soil of grasslands; and the domestication of animals cre-ated a dependable food supply. This, in turn, gave rise to the first major civilizations in an areathat became known as the Fertile Crescent, which was in an area near the Tigris and Euphratesrivers in the Middle East. Overuse of the land, however, eventually caused the land to yieldless food, and the civilizations declined. Today, much of the Fertile Crescent is desert.

In the eighteenth century, the IndustrialRevolution brought a shift from the smallscale production of hand-made goods to thelarge scale production of machine-madegoods. As a result, industrialized countriesshifted from rural, agricultural basedeconomies to economies that were more urbanand industrial. The introduction of largeindustrial factories brought about a new era ofenvironmental pollution.

From the Industrial Revolution arose many advances in technology, medicine, and transporta-tion. Together, these resulted in a dramatic growth in world population, which had grown veryslowly prior to the Industrial Revolution. Current projections indicate that the human popula-tion, which today is around five billion, will double in about 30 years.


By the 1950’s, many researchers feared that the rate of population growth would outpace therate of food production, resulting in a global famine. Fortunately, food production increased asnew crop varieties were introduced and systems of intensive agricultural practices were devel-oped. Commonly called the “Green Revolution,” this era resulted in dramatic increases cropyields, but also brought unforeseen impacts on the environment. For example, pesticides usedto control crop-devastating insects also killed other organisms. What’s more, these practicesrequire immense amounts of energy, thereby depleting oil reserves and releasing pollutants.


Study Guide #2

ENVIRONMENTAL POLLUTION

Pollution is anything that makes the environment less suitable for living things. Pollutantsinclude chemicals and other substances, as well as noise & heat. Although much environmen-tal pollution today is the result of human activity, it is important to note that many naturalevents such as volcanoes or fires, also produce pollutants.

Environmentally speaking, pollutants are released by a source. The area that a pollutant isreleased to is called a sink. We can track a pollutant from a source to a sink through intercon-nected environmental compartments. These include air; water; land; and the biota, or livingthings.

One of the most profound impacts human activ-ity has had on the environment is air pollution.Air pollution is believed to have resulted inozone depletion, global warming, smog, andacid deposition.

The earth’s atmosphere is comprised of 4 lay-ers. One of the intermediate layers, the strato-spherecontains a diffuse layer of a gas knownas ozone, which protects the planet from mostof the sun’s harmful Ultraviolet , or UV light . Overexposure to UV light, which is also calledUV radiation, causes sunburn, cancer, and blindness, and can even kill microbes, plants, andanimals.

In the formation of ozone in the stratosphere, UV light splits an oxygen (O2 ) molecule intotwo oxygen atoms. If one of these atoms combines with an oxygen

molecule, ozone (O3 ) is formed. Balance ismaintained between ozone and oxygen concen-trations as some of the ozone molecules natu-rally degrade to oxygen. When ozone (O3 )absorbs UV light, it splits into an oxygen mol-ecule (O2 ) and an oxygen atom (O). If thisoxygen atom combines with another ozonemolecule, the end product is two oxygen mole-cules. This cycle can then begin again.Absorbtion of UV light that drives these reac-tions prevents some of the UV light fromreaching the Earth’s surface.


Scientists estimate that since 1979, the ozonelayer over Antarctica has decreased annually by 50%. We call the area of diminished ozone con-centration an ozone hole. While this ozone holedisappears each year due to seasonal wind pat-terns, its maximum extent has grown every yearsince measurements began. A lower concentra-tion of ozone means that more of the sun’sharmful UV light is reaching the earth’s surface.

While a variety of chemicals may be to blamefor the depletion of the ozone layer, man-made chlorofluorocarbons, or CFCs, certainly play arole. CFCs are emitted to the atmosphere through aerosol sprays, refrigeration, dry-cleaning,and plastic foam. Once they are released, CFCs eventually rise to the stratosphere. When

exposed to UV light, a CFC molecule willrelease a chlorine (Cl) atom. Chlorine thensteals an oxygen atom from ozone. This newmolecule of chlorine and oxygen then takesanother oxygen atom from a different ozonemolecule. Next, the two oxygen atoms com-bine to make an oxygen molecule (O2 ), leav-ing the chlorine atom free to begin the cycleagain. With CFCs remaining in the atmos-phere for decades, this cycle repeats thousandsof times, disrupting the natural concentrationof ozone. Fortunately, international efforts to

eliminate the use of CFCs have been introduced, though some countries still produce CFCs.

In addition to depleting the ozone layer, air pollution has lead to global warming. The sun sup-plies energy that warms the atmosphere, but the earth is actually heated from the surface up.As sunlight heats the earth’s surface, certain gases, such as methane, CFCs, water vapor, andcarbon dioxide, trap heat and also reradiate energy back to the Earth’s surface. Scientists callthis phenomenon the Greenhouse Effect, because the gases act like the windows of a green-house, letting light in, but preventing heat fromescaping.

Carbon dioxide concentrations in the atmos-phere naturally vary with the seasons. Plantsabsorb carbon dioxide during the growing sea-son. Later, when organisms breakdown leavesand other plant parts, the carbon dioxide isreleased. Carbon dioxide concentrations haveincreased steadily over time due primarily tothe combustion of fossil fuels by humans.Since carbon dioxide is a greenhouse gas – a gas that traps heat in the earth’s atmosphere – ele-Copyright 1999 CyberEd ™ Inc. 7

vated concentrations of this gas may potentially increase the earth’s average temperature. Thisrise in the earth’s temperature is called global warming, and it can alter rainfall, storm activity,and cloud formation. In a more extreme scenario, global warming could melt polar ice capsand raise sea levels, increase weather extremes, and induce crop failures.

Another type of air pollution is industrialsmog, which is the combination of smoke andfog. Although regulations on coal burning havegreatly reduced the amount of industrial smogin recent years, increased usage of oil andgasoline has given rise to photochemicalsmog. Cars, power plants, and other sourcesrelease the chemical precursors to photochemi-cal smog. In the presence of sunlight, thesechemicals produce an acidic, reddish-brownhaze that irritates people’s eyes, causes respira-

tory problems, and stunts plant growth. Mountains and temperature inversions can trap theseair pollutants close to the ground.

Pollutants do not have to remain airborne to cause problems. Wind can carry airborne chemi-cal pollutants hundreds of miles before they settle to the ground. The fall of pollutants to theground is called acid deposition. Acid rain is a type of acid deposition. Acid rain occurswhen rain carries airborne chemical pollutants to the ground. In sensitive areas, acid depositionkills plants and aquatic animals, and dissolves building materials. After falling to the ground,acid deposition can often pollute water sources.

There are two general types of sources of waterpollutants. A point sourcereleases pollutantsdirectly into a body of water, such as a factorypipe that releases waste directly into an ocean,lake, or stream. A non-point sourceis lesswell-defined, and includes city street runoff,for example.

Water pollutants can be divided into six maincategories: organic substances, which aredivided into biodegradableand nonbiodegradable substances; inorganic chemicals, whichare divided into metals and nutrients; water-borne pathogens; thermal releases; petroleumhydrocarbons; and radioactive wastes. Several of these pollutants produce similar effects.For example, non-biodegradable organic substances, inorganic chemicals, petroleum hydrocar-bons, and radioactive wastes can be extremely poisonous to organisms, while thermal releasesand biodegradable organic wastes in lakes and streams can produce enormous amounts of algae,a condition called an algal bloom. Algal blooms can stifle plant growth and kill fish and otherorganisms. Also, excessive amounts of biodegradable waste can result in eutrophication. Bythis process, a high nutrient load reduces a lake’s size, depth, and clarity. Copyright 1999 CyberEd ™ Inc. 8

A thermal release is the discharge of heatedwater from industrial plants into rivers or lakes.In addition to causing algal blooms, thermalreleases can directly harm ectothermic aquaticorganisms. Unlike endothermic animals, suchas mammals and birds, the body temperature ofmost aquatic organisms, such as fish, crayfish,and insects, varies with environmental tempera-ture, making them sensitive to temperaturechanges.

Another potential problem from water pollution, is the biological magnification of some metalsand non-biodegradable organic chemicals. Biological magnification, which is also called bioac-cumulation or bioconcentration, occurs when chemical concentrations are amplified in each stepupward in a food chain. The pesticide DDT, for instance, is found in low concentrations inwater and algae. However, as zooplankton eat the algae and fish eat the zooplankton, the con-centrations of DDT increase in the higher organisms. The DDT concentrations in the highesttrophic levels, such as that found in a top consumerlike the Brown Pelican, can be much high-er than the concentrations found in the tissues of lower level consumers or producers.

Many pollutants in air and water actually originate from activities on land, such as pesticideapplication, mining, or hazardous waste disposal. These activities first contaminate soil, and inturn water and air, with harmful chemicals.

Also of environmental concern is the volumeof personal waste. Each person in the UnitedStates, annually produces about 20 times theirbody weight in garbage, and most of thiswaste ends up in landfills . As a result, manycommunities are running out of room in exist-ing landfills and are having difficulty locatingnew facilities. As a solution, many communi-ties promote programs that encourage peopleto reduce waste, reuse, and recycle. Theseprograms divert waste from landfills and pro-vide profits as some communities sell recycled materials.

Pollution is an important issue because it eventually affects the earth’s biota, or living things.In some cases, pollution has decimated large fish populations. Adverse effects of pollution,however, are not always so obvious. For example, polluting compounds called endocrine dis-rupters mimic hormones and can cause offspring to be mainly of one sex.

Although pollution remains a serious problem, progress has been made in its reduction.Regulations have improved air and water quality in many parts of the world. For example,Copyright 1999 CyberEd ™ Inc. 9

power plants use technology to remove pollutants from smokestacks and water outflows, andstates such as California require strict emission controls on new cars. What’s more, attitudesabout controlling pollution are changing. Some companies try to anticipate environmentalproblems before they arise by using Product Life-Cycle Assessments (or PLCAs). PLCAsexamine the production, use, and disposal of products to determine how to reduce pollution andbetter comply with environmental laws. Such approaches reveal new uses for former wastesand often develop procedures that reduce costs for the company.


Study Guide #3

HABITAT DESTRUCTION, NATURAL RESOURCE DEPLETION, AND THE LOSSOF BIODIVERSITY

The place where an organism normally lives is its habitat. Habitats include forests, wetlands,and grasslands, which are often destroyed to make room for factories, freeways, farms, and

other facilities. Agriculture still occupies moreland than any other activity, but cities aregrowing rapidly. Poor planning, growing pop-ulations, and reliance on the automobile fortransportation contribute to urban sprawl,which is the spread of cities over large areas.Land conversion can bring about benefits, butit interrupts important ecosystem functions andoften replaces rare habitats with those that aremore common. Building on former wetlands,for example, displaces endangered species, anddecreases water quality and flood-water stor-

age. These natural wetland functions would be expensive or perhaps impossible to duplicate.

A natural resource is any finite substance obtained from the environment that is used by anorganism. Natural resources used by humans include soil, trees, fish, petroleum, and water.Along with industrialization, as the human population continues to grow, many naturalresources are showing signs of overuse.

Overuse of soil has lead to soil erosion. Topsoil is the nutrient-rich upper layer of soil that iscritical for plant growth. Vegetation protectstopsoil from heavy winds and water. Poorforestry or agricultural practices can removeprotective vegetation and increase soil erosion.Soil erosion occurs when water or wind carriestopsoil away leaving only coarse, nutrient-poor,sandy soil or bedrock. If this cycle continuesover time, especially in conjunction withdrought or climate change, desertificationoccurs and results in land far less productivethan its original state. Desertification wasresponsible for transforming the Fertile Crescent from a thriving agricultural area to an area thatis now mostly desert. In the past 40 years, desertification has caused farmers to abandon up to30% of cropland worldwide.

Forests are the main source of timber, paper, charcoal, turpentine and rayon. They also providecritical ecological functions, such as the absorption of carbon dioxide from the environment.Tree harvesting increases a forest’s susceptibility to disease, soil erosion, fires, and weed inva-Copyright 1999 CyberEd ™ Inc. 11

sion. Deforestation is the removal of trees from an area without adequate replanting or regen-eration. Replanting clear-cut areas often protects soil, but does not always duplicate the impor-tant qualities of old-growth forests. Old-growth forests are forests that have never been cutand possess a variety of habitats and food sources that support many different species of organ-isms. Once a forest is cleared, recovery can be slow.

Although oceans cover much of the Earth,most of the fish and shellfish caught each yearcome from relatively small areas. The reasonfor this is that as organisms die they settle tothe ocean bottom. If the bottom is shallow, thenutrients are recycled. If the bottom is toodeep, the nutrients sink to a depth where theyare inaccessible and cannot be used. In someareas, certain ocean currents, calledupwellings, bring nutrients up from the bot-tom. Upwellings allow algae to flourish, attracting fish and fishermen. Despite efforts to con-serve fish populations, the number of fish caught globally has remained stable since 1980 andthe numbers of the most important species for food have been reduced. In response to over-fishing, many countries have limited the catch of fish. The development of aquaculture or fishfarming techniques may also help lessen the pressure on the world’s fisheries.

On average, a person drinks about 2 liters ofwater each day. About 300 times that amountis used every day for industrial processes,growing crops, and household uses. To satisfyour water needs, as well as to provide floodcontrol and generate hydroelectric power,dams, levees, and water diversions have beenbuilt. These projects dramatically alter aquatichabitats, and place many species at risk. Inaddition to the immediate ecological effects ofsuch projects, adverse long-term effects mayalso arise.

Water for human use is also pumped from underground sources called aquifers. An aquiferforms as rainfall infiltrates, or soaks into the soil and collects in underground layers of rock,sand, or gravel. As long as water inflow matches outflow, groundwater levels remain the same.Over-pumping, however, can result in a settling downward of the land surface known as landsubsidence. Subsidence permanently decreases an aquifer’s ability to hold water. In the highplains of the US, over-pumping threatens the Ogallala Aquifer, one of the world’s largestaquifers.

Soil, forests, oceans, and water are potentially renewable resources. If used conservatively,renewable resources will replenish themselves indefinitely. Sustainable methods allow the useCopyright 1999 CyberEd ™ Inc. 12

of resources without depleting them. Manysustainable practices are currently practicedthroughout the world, but political and eco-nomic concerns often interfere with these prac-tices.

Habitat destruction and the depletion of naturalresources can result in the loss of biodiversity. Biodiversity is the variety of genetic informa-tion, species, and communities in an ecosys-tem. Around the world, human activities haveincreasingly put species at risk of extinction, which is the death of an entire species. Extinctiondecreases biodiversity.

Biodiversity is important for a variety of reasons. Ecosystems with high biodiversity recoverbetter from disturbances such as fires, than similar ecosystems with low biodiversity.Furthermore, species that have not yet been discovered may provide new crops, medicines, andother products if they are studied and saved from extinction. Also, threatened speciesmayplay essential roles in ecosystems that we may not yet understand.


Study Guide #4

Conservation biology is the application of scientific methods to preserve biodiversity.Conservation strategies include saving individ-ual species, establishing preserves, and restor-ing degraded ecosystems.

Although environment problems resulting fromhuman impacts can seem overwhelming, solu-tions are not impossible. Cooperation amonggovernments, businesses, and communities isessential to create programs for curbing envi-ronmental pollution, slowing habitat conver-sion, preventing overuse of natural resources,and stopping the loss of biodiversity. Also,

several things can be done on the individual level to help control human impacts on the envi-ronment. For example, you can choose a career that develops solutions to these problems.Environmental engineers devise innovative solutions to dispose of hazardous waste or recyclewaste material. You can volunteer with organ-izations that preserve or restore the environ-ment. As a consumer, you can buy environ-mentally friendly products, and thereby per-suade businesses to offer more of these typesof products. As a voter, you can vote formeasures of conservation, and impact thedirection of environmental laws for future gen-erations. Several solutions to our environmen-tal problems are available. It is our responsi-bility to see that they are carried out.


HUMAN IMPACTS ON THE ENVIRONMENTQUIZ PAC

The following quizzes are meant to assess student understanding of specific areas covered inthe Interactive Multimedia Courseware program, Human Impacts on the Environment.


Quiz #1 Human Impacts: A Brief HistoryQuiz #2 Environmental PollutionQuiz #3 Habitat Destruction, Natural Resource

Depletion and loss of BiodiversityQuiz #4 Methods of Conservation

Quiz #1

HUMAN IMPACTS: A BRIEF HISTORY

1. Early humans lived a ______________ lifestyle.sessileA. slash and burnB. hunter-gathererC. Green Revolution

2. Our human ancestors had no impact on the environment in which they lived.A. TrueB. False

3. Humans were able to create a dependable food supply through____________.slash and burn farmingA. the domestication of animalsB. the invention of the plowC. all of the above

4. The first major human civilizations were formed in an area called _____________.A. the Fertile CrescentB. EnglandC. GermanyD. the Green Revolution

5. In the eighteenth century, the _______________ brought a shift from the small scale production of hand-made goods to the large scale production of machine-made goods.A. fertile CrescentB. green RevolutionC. industrial RevolutionD. desertification

6. ___________________ came about in the 1950’s and increased food production.A. The Green RevolutionB. The Fertile CrescentC. The Industrial RevolutionD. Hunter-gatherer lifestyles

7. The _______________ led to many advances in technology, medicine, and transportation.

A. fertile CrescentB. green RevolutionC. industrial Revolution


D. desertification

8. The Industrial Revolution caused many countries to shift from an urban, industrial economy to an economy that was more rural and based in agriculture.A. True B False

9. The _________________ brought about many pesticides and increased crop yields, but also resulted in environmental pollution.A. hunter-gatherer lifestylesB. Fertile CrescentC. Green RevolutionD. none of the above

10. The earth’s population is expected to ______________ in the next thirty years.doubleA. remain about the sameB. quadrupleC. decline


Quiz #2

ENVIRONMENTAL POLLUTION

1. Which of the following are considered pollutants?A. chemicalsB. noiseC. anything that makes the environment less suitable for living thingsD. all of the above

2. Natural events, such as volcanic eruptions and forest fires, produce pollutants.A. TrueB. False

3. Pollutants are released by a ____________ and absorbed by a ____________.A. sink, sourceB. source, sinkC. producer, consumerD. consumer, producer

4. Air pollution causes all of the following except _______________.A. ozone depletionB. smogC. acid depositionD. air pollution causes all of the above

5. The ______________ is found in the stratosphere and protects the earth from the sun’s harmful UV light.A. greenhouse effectB. CFCC. ozone layerD. smog layer

6. Ozone is formed when ______________. A. an oxygen atom previously split by UV light combines with an oxygen molecule B. UV light splits an oxygen molecule C. chlorine combines with an oxygen atomD. two oxygen atoms combine

7. Scientists predict that the ozone hole _________________.A. is growing in sizeB. disappears each year due to seasonal wind patternsC. is becoming smallerD. A and B


8. The chemicals most responsible for depleting the ozone layer are called________________.A. chlorofluorocarbonsB. CFCsC. carbon dioxide and sulfur dioxideD. A and B

9. Some aerosol sprays contain chemicals that deplete the ozone layer.A. TrueB. False

10. _______________ may occurs when certain gases in the atmosphere, such as carbon dioxide and methane trap heat and raise the atmosphere’s temperature. A. The Green RevolutionB. The greenhouse effectC. Acid depositionD. Photochemical smog

11. The amount of carbon dioxide in the atmosphere is _____________.A. decreasingB. remaining about the sameC. increasingD. of little concern

12. Global warming could ______________.A. alter weather patternsB. induce crop failuresC. raise sea levelsD. all of the above

13. The combination of smoke and fog is called ______________.A. acid rainB. industrial smogC. photochemical smogD. acid deposition

14. _________________ is formed when chemicals released from cars, power plants and other sources, react in the presence of sunlight to produce an acidic, reddish-brown hazethat is known to cause respiratory problems.A. Acid rainB Industrial smogC. Photochemical smogD. Acid deposition


15. The fall of pollutants to the ground is called ______________.A. acid depositionB. industrial smogC. the greenhouse effectD. photochemical smog

16. In water pollution, a _____________ releases pollutants directly into a body ofwater, while a ______________ is less direct, such as city street runoff.A. point source, point sinkB. non-point source, point sourceC. point source, non-point sourceD. point sink, non-point sink

17. Water pollutants include all of the following except ______________. A. metalsB. nutrientsC. thermal releasesD. PLCAs

18. Thermal releases and biodegradable organic wastes in lakes and streams cancause _____________, in which algae stifle plant growth and kill fish and otherorganisms.A. industrializationB. desertificationC. an algal bloomD. biological magnification

19. Through the process of ______________, a high nutrient load reduces a lake’ssize, depth, and clarity.A. eutrophicationB. desertificationC. industrializationD. biological magnification

20. _________________ occurs when chemical concentrations are amplified up the food chain.A. Algal bloomB. EutrophicationC. Acid depositionD. Biological magnification

21. Pollutants called ______________, can mimic hormones, causing offspring to be mainly of one sex.A. petroleum hydrocarbonsB. water-borne pathogens


C. endocrine disruptersD. thermal releases

22. In order to counteract the overfilling of landfills, communities should ___________.recycleA. reduce their amount of wasteB. reuse materialsC. all of the above

23. Regulations have improved air and water quality in many parts of the world.A. TrueB. False

24. Each year in the United States, each person produces about __________ timestheir body weight in garbage.A. threeB. three hundredC. twentyD. ten

25. Some companies try to anticipate environmental problems before they arise byusing ________________ , which examine the production, use, and disposal ofproducts to determine how to reduce pollution and better comply withenvironmental laws. A. CFCsB. Product Life-Cycle Assessments (PLCAs)C. biological magnificationsD. the greenhouse effects


Quiz #3

HABITAT DESTRUCTION, NATURAL RESOURCE DEPLETION, AND LOSS OFBIODIVERSITY

1. A habitat is _______________.A. a place in which an organism usually livesB. a grasslandC. a forestD. all of the above

2. Urban sprawl, or the spreading out of cities over large areas, is the result of _____________.A. poor city planningB. growing populationsC. our reliance on the automobile for transportationD. all of the above

3. When poor forestry or agricultural practices remove vegetation that protects nutrient-rich topsoil from heavy rains and wind, ______________ increases.A. soil erosionB. desertificationC. A and BD. None of the above

4. Soil erosion, weed invasion, and habitat destruction can all occur as a result of ______________, which is the removal of trees from an area without adequatereplanting or regeneration.A. deforestationB. desertificationC. recyclingD. conservation

5. A _______________ is any finite substance obtained from the environment that isused by an organism. A. pollutantB. CFCC. natural resourceD. habitat

6. An old-growth forest ______________.A. is a forest that has never been cutB. has a variety of habitats and food sourcesC. is home to a variety of organismsD. all of the above


7. Fish and shellfish are abundant throughout most areas of the earth’s oceans.A. TrueB. False

8. Many aquatic habitats have been disrupted by dams, levees, and water diversions.A. TrueB. False

9. A(n) ______________ forms as rainfall infiltrates, or soaks, into the soil and collectsin underground layers of rock, sand, or gravel.A. algal bloomB. landfillC. aquiferD. none of the above

10. Soil, forests, oceans, and water are potentially renewable resources that willreplenish themselves if used conservatively.A. TrueB. False

11. ______________ can decrease an aquifer’s ability to hold water.A. DeforestationB. DesertificationC. OverpumpingD. Overfishing

12. The variety of genetic information, species, and communities in an ecosystemmakes up the ecosystem’s ______________. A. habitatB. natural resourcesC. ozone layerD. biodiversity

13. Extinction of a species increases biodiversity.A. TrueB. False

14. Ecosystems with high biodiversity recover better from disturbances such as fires,than similar ecosystems with low biodiversity.A. TrueB. False


Quiz #4

METHODS OF CONSERVATION

1. The application of scientific methods to preserve biodiversity has created the field of ____________.A. conservation biologyB. geneticsC. physiologyD. conversational biology

2. Methods of conservation include all of the following except ______________. A. saving individual speciesB. establishing preservesC. restoring degraded ecosystemsD. clear-cutting forests

3. In order to create conservation programs cooperation is required among ____________.A. governmentsB. businessesC. communitiesD. all of the above

4. Environmental engineers devise innovative solutions to such environmentalproblems as the disposal of hazardous waste.A. TrueB. False

5. As an individual, you can contribute to conservation by ___________.A. choosing a career that develops solutions to environmental problemsB. volunteering with organizations that preserve and restore the environmentC. voting for measures of conservationD. all of the above


Human Impacts on the EnvironmentCOMPREHESIVE EXAM

Directions: Answer each of the following questions as either “True” or “False.”

1. Natural events, such as volcanic eruptions and forest fires, produce pollutants.A. TrueB. False

2. Some aerosol sprays contain chemicals that deplete the ozone layer.A. TrueB. False

3. Regulations have improved air and water quality in many parts of the world.A. TrueB. False

4. Our human ancestors had no impact on the environment in which they lived.A. TrueB. False

5. The Industrial Revolution caused many countries to shift from an urban, industrial economy to an economy that was more rural and based in agriculture.A. True B. False

6. Fish and shellfish are abundant throughout most areas of the earth’s oceans.A. TrueB. False

7. Many aquatic habitats have been disrupted by dams, levees, and water diversions.A. TrueB. False

8. Soil, forests, oceans, and water are potentially renewable resources that willreplenish themselves if used conservatively.A. TrueB. False

9. Extinction of a species increases biodiversity.A. TrueB. False


10. Environmental engineers devise innovative solutions to such environmentalproblems as the disposal of hazardous waste.A. TrueB. False

Directions: Choose the correct answer to each multiple-choice question.

11. Early humans lived a ______________ lifestyle.A. sessileB. slash and burnC. hunter-gathererD. Green Revolution

12. Humans were able to create a dependable food supply through____________.A. slash and burn farmingB. the domestication of animalsC. the invention of the plowD. all of the above

13. The first major human civilizations were formed in an area called _____________.the Fertile CrescentA. EnglandB. GermanyC. the Green Revolution

14. In the eighteenth century, the _______________ brought a shift from the small scale production of hand-made goods to the large scale production of machine-made goods.A. fertile CrescentB. green RevolutionC. industrial RevolutionD. desertification

15. ___________________ came about in the 1950’s and increased food production.A. The Green RevolutionB. The Fertile CrescentC. The Industrial RevolutionD. Hunter-gatherer lifestyles

16. The _______________ led to many advances in technology, medicine, and transportation.A. fertile CrescentB. green RevolutionC. industrial Revolution


D. desertification

17. The _________________ brought about many pesticides and increased crop yields, but also resulted in environmental pollution.A. hunter-gatherer lifestylesB. fertile CrescentC. green RevolutionD. none of the above

18. The earth’s population is expected to ______________ in the next thirty years.A. doubleB. remain about the sameC. quadrupleD. decline

19. Which of the following are considered pollutants?A. chemicalsB. noiseC. anything that makes the environment less suitable for living thingsD. all of the above

20. Pollutants are released by a ____________ and absorbed by a ____________.A. sink, sourceB. source, sinkC. producer, consumerD. consumer, producer

21. Air pollution causes all of the following except _______________.A. ozone depletionB. smogC. acid depositionD. air pollution causes all of the above

22. The ______________ is found in the stratosphere and protects the earth from the sun’s harmful UV light.A. greenhouse effectB. CFCC. ozone layerD. smog layer

23. Ozone is formed when ______________. A. an oxygen atom previously split by UV light combines with an oxygen molecule B. UV light splits an oxygen molecule C. chlorine combines with an oxygen atomD. two oxygen atoms combine


24. Scientists predict that the ozone hole _________________.A. is growing in sizeB. disappears each year due to seasonal wind patternsC. is becoming smallerD. A and B

25. The chemicals most responsible for depleting the ozone layer are called________________.A. chlorofluorocarbonsB. CFCsC. carbon dioxide and sulfur dioxideD. A and B

26. _______________ may occur when certain gases in the atmosphere, such as carbon dioxide and methane trap heat and raise the atmosphere’s temperature. A. The Green RevolutionB. The greenhouse effectC. Acid depositionD. Photochemical smog

27. The amount of carbon dioxide in the atmosphere is _____________.A. decreasingB. remaining about the sameC. increasingD. of little concern

28. Global warming could ______________.A. alter weather patternsB. induce crop failuresC. raise sea levelsD. all of the above

29. The combination of smoke and fog is called ______________.A. acid rainB. industrial smogC. photochemical smogD. acid deposition

30. _________________ is formed when chemicals released from cars, power plants and other sources, react in the presence of sunlight to produce an acidic, reddish-brown hazethat is known to cause respiratory problems.A. Acid rainB. Industrial smogC. Photochemical smog


D. Acid deposition

31. The fall of pollutants to the ground is called ______________.A. acid depositionB. industrial smogC. the greenhouse effectD. photochemical smog

32. In water pollution, a _____________ releases pollutants directly into a body ofwater, while a ______________ is less direct, such as city street runoff.A. point source, point sinkB. non-point source, point sourceC. point source, non-point sourceD. point sink, non-point sink

33. Water pollutants include all of the following except ______________. A. MetalsB. nutrientsC. thermal releasesD. PLCAs

34. Thermal releases and biodegradable organic wastes in lakes and streams cancause _____________, in which algae stifle plant growth and kill fish and otherorganisms.A. industrializationB. desertificationC. an algal bloomD. biological magnification

35. Through the process of ______________, a high nutrient load reduces a lake’ssize, depth, and clarity.A. eutrophicationB. desertificationC. industrializationD. biological magnification

36. _________________ occurs when chemical concentrations are amplified up the A. food chain.B. Algal bloomingC. EutrophicationD. Acid depositionE. Biological magnification

37. Pollutants called ______________, can mimic hormones, causing offspring to be mainly of one sex.


A. petroleum hydrocarbonsB. water-borne pathogensC. endocrine disruptersD. thermal releases

38. In order to counteract the overfilling of landfills, communities should ___________.A. recycleB. reduce their amount of wasteC. reuse materialsD. all of the above

39. Each year in the United States, each person produces about __________ timestheir body weight in garbage.A. threeB. three hundredC. twentyD. ten

40. Some companies try to anticipate environmental problems before they arise byusing ________________ , which examine the production, use, and disposal ofproducts to determine how to reduce pollution and better comply withenvironmental laws. A. CFCsB. Product Life-Cycle Assessments (PLCAs)C. Biological magnificationsD. the greenhouse effect

41. A habitat is _______________.A. a place in which an organism usually livesB. a grasslandC. a forestD. all of the above

42. Urban sprawl, or the spreading out of cities over large areas, is the result of _____________.A. poor city planningB. growing populationsC. our reliance on the automobile for transportationD. all of the above

43. When poor forestry or agricultural practices remove vegetation that protects nutrient-rich topsoil from heavy rains and wind, ______________ increases.A. soil erosionB. desertificationC. A and B


D. None of the above

44. Soil erosion, weed invasion, and habitat destruction can all occur as a result of ______________, which is the removal of trees from an area without adequateA. replanting or regeneration.B. deforestationC. desertificationD. recyclingE. conservation

45. A _______________ is any finite substance obtained from the environment that isused by an organism. A. pollutantB. CFCC. natural resourceD. habitat

46. An old-growth forest ______________.A. is a forest that has never been cutB. has a variety of habitats and food sourcesC. is home to a variety of living thingsD. all of the above

47. A(n) ______________ forms as rainfall infiltrates, or soaks, into the soil and collectsin underground layers of rock, sand, or gravel.A. algal bloomB. landfillC. aquiferD. none of the above

48. ______________ can decrease an aquifer’s ability to hold water.A. DeforestationB. DesertificationC. OverpumpingD. Overfishing

49. The variety of genetic information, species, and communities in an ecosystemmakes up the ecosystem’s ______________. A. habitatB. natural resourcesC. ozone layerD. biodiversity

50. The application of scientific methods to preserve biodiversity has created the field of ____________.


A. conservation biologyB. geneticsC. physiologyD. conversational biology

51. Methods of conservation include all of the following except ______________. A. saving individual speciesB. establishing preservesC. restoring degraded ecosystemsD. clear-cutting forests

52. In order to create conservation programs cooperation is required among ____________.A. governmentsB. businessesC. communitiesD. all of the above

53. As an individual, you can contribute to conservation by ___________.A. choosing a career that develops solutions to environmental problemsB. volunteering with organizations that preserve and restore the environmentC. voting for measures of conservationD. all of the above


Human Impacts on the EnvironmentANSWER KEY

Quizzes


Question # 1 2 3 41. C D D A2. B A D D3. D B C D4. A D A A5. C C C D6. A A D7. C D B8. B D A9. C A C10. A B A11. C C12. D D13. B B14. C A15. A16. C17. D18. C19. A20. D21. C22. D23. A24. C25. B

1. A 12. D 23. A 34. C 45. C2. A 13. A 24. D 35. A 46. D3. A 14. C 25. D 36. D 47. C4. B 15. A 26. B 37. C 48. C5. B 16. C 27. C 38. D 49. D6. B 17. C 28. D 39. C 50. A7. A 18. A 29. B 40. B 51. D8. A 19. D 30. C 41. D 52. D9. B 20. B 31. A 42. D 53. D10. A 21. D 32. C 43. C11. C 22. C 33. D 44. A

Comprehensive Exam

Human Impacts on the EnvironmentGLOSSARY

acid: a chemical compound that increases the hydrogen ion concentration in a solution.

acid deposition: the falling of acids or acid forming chemicals through the atmosphere to theEarth’s surface. These chemicals can fall as precipitation (rain, sleet, snow, hail, etc.) or dryparticles.

agriculture: the practice of farming.

algal bloom: the proliferation of algae in a body of water, usually due to high concentrations ofnutrients.

aquifer: an underground layer of rock, sand, or gravel in which water can pass or be stored.

atom: smallest unit of a chemical element.

biodegradable substance: organic material that can be broken down by organisms into simplersubstances.

biodiversity: the variety of living things and includes genetic information, species, and commu-nities in an ecosystem.

biological magnification: the accumulation of substances such as toxic metals and chemicals inorganisms at higher trophic levels of the food chain. Biological magnification is sometimescalled bioaccumulation or bioconcentration.

biota: all the living organisms in a certain area or region.

chlorofluorocarbon (CFC): a synthetic, or man-made, organic molecule that contains both chlo-rine and fluorine atoms. CFCs are used in refrigerants, aerosol sprays, dry-cleaning, and tomake plastic foam.

clear cut: a timber harvest method in which all trees in an area are cut.

climate: temperature range, average annual precipitation, humidity, and the amount of solarenergy that a region typically experiences.

conservation biology: the application of biological principles to preserve biodiversity and natu-ral resources.

consumer: an organism that must eat other organisms for energy.

Costa Rica: a country in Central America.Copyright 1999 CyberEd ™ Inc. 34

DDT: Dichlorodiphenyltrichloroethane, a pesticide once widely used throughout the world,now banned in many countries because of a variety of unintended adverse impacts.

deforestation: the harvest of trees without adequate replanting.

desertification: the unintentional conversion of agricultural land into less productive desert-likeland. Usually caused by a combination of overgrazing, soil erosion, prolonged drought, and/orclimate change.

ecosystem: a biological community and the physical and chemical environment with which itinteracts.

ectothermic: organisms, such as crustaceans, fish, amphibians, or reptiles, that rely on environ-mental temperature to control body temperature. These animals are commonly known as cold-blooded animals.

emission: the release of substances into the environment.

endangered species: a species whose population is declining to low levels throughout its range,and may eventually face extinction.

endocrine disrupter: a chemical that mimics hormones and disrupts normal physiology of ani-mals.

environment: all of the living and non-living factors that affect organisms.

environmental compartment: one of various divisions of an ecosystem: air, water, soil, or biota.

environmental impact: the disruption of normal ecosystem function.

eutrophication: an increase in nutrient load that changes the chemical, physical, and biologicalcharacteristics of a water body. Eutrophication often accelerates sedimentation, increases plantgrowth, and decreases water quality.

extinction: the disappearance of a species from Earth, either from natural or human-causedchanges in the environment.

Fertile Crescent: an area that includes the Nile River in Africa through the present day loca-tions of Israel, Syria, Iraq, and Kuwait, and is one of the principal locations of early agriculturalcivilization.

fish kill: the death of large numbers of fish due to disease or pollution.


fossil fuel: an energy source such as oil, formed from the deposition and compaction of ancientorganisms and organic matter.

global warming: the theory that human contributions to the greenhouse effect will cause a sig-nificant rise in Earth’s average temperature.

greenhouse effect: retention of heat in Earth’s atmosphere due to the presence of greenhousegases. Human activities increase the presence of these gases in the atmosphere.

greenhouse gas: vapors such as methane, CFCs, water vapor, carbon monoxide, carbon diox-ide, and other chemicals that trap heat in the atmosphere.

Green Revolution: an intensive system of agricultural practices, beginning in the mid 1900s,that dramatically increased crop yields.

habitat: the type of place where an organism lives.

hunter-gatherer: a human who survives by hunting animals and gathering food from the naturalenvironment.

Industrial Revolution: the application of technology and automation to industry, medicine, sci-ence, and transportation. The Industrial Revolution began in England in the late 1700s.

industrial smog: a grayish mixture of moisture, soot, and sulfurous compounds that occurswhere industries are concentrated and coal is the primary energy source.

inorganic chemical: various elements and compounds that do not include carbon-based organicmolecules.

landfill: a place where waste is deposited and subsequently buried underground.

metal: an element with certain characteristic physical properties. Examples include mercury,lead, iron, and copper.

molecule: agroup of atoms bonded together in a specific fashion.

Montreal Protocol: an international agreement which intends to limit the production and use ofCFCs.

non-biodegradable substance: usually synthetic, or man-made materials that do not readilybreak down in nature.

non-point source: pollution from a diffuse area, such as agricultural or urban runoff. Thesesources may contain sediment, fertilizers, pesticides, and other materials. Copyright 1999 CyberEd ™ Inc. 36

nutrient: element or compound needed for the survival, growth, and/or reproduction of anorganism.

old growth forest: a forest that has never been cut or adversely affected by humans. An oldgrowth forest often supports complex communities.

organic chemical: a molecule or compound (groups of molecules) containing the elements car-bon, hydrogen, and often oxygen or other elements. Organic molecules have a biologic origin.

overfishing: the harvesting of fish and other aquatic organisms in an unsustainable manner.

overpumping: the removal of water from underground sources that results in depletion of thegroundwater supply.

ozone: atmospheric gas molecules consisting of three oxygen atoms (O3). Ozone is a pollutantin the troposphere, or lower atmosphere, but screens out ultraviolet radiation in the stratosphere,or upper atmosphere.

ozone depletion: the reduction of ozone concentrations in the ozone layer.

ozone hole: a region of the stratosphere that is severely depleted of its normal levels of ozone,presumably due to the action of natural and man-made chemicals.

ozone layer or shield: a diffuse layer of ozone in the stratosphere that shields the Earth’s sur-face from most of the harmful effects of UV radiation.

petroleum hydrocarbon: any compound that comes from crude oil including oil, diesel, gas,and kerosene.

photochemical smog: the reddish-brown haze that frequently forms on otherwise clear sunnydays over large cities with significant amounts of automobile traffic. Emissions react in thepresence of sunlight to produce the acidic, irritating smog.

poison: any chemical that destroys or harms life.

point source: pollutants coming from a clearly identifiable source such as a factory or sewageoutlets.

pollutant: any natural or artificial substance that enters the environment in such quantities thatit harms the ecosystem and makes the environment less suitable for living things.

pollution: the release of anything that makes the environment less suitable for living things.

producer: organisms, such as plants or photosynthetic bacteria, that make their own food fromCopyright 1999 CyberEd ™ Inc. 37

inorganic substances.

Product Life-cycle Assessments (PLCAs): a process that examines products from their produc-tion to disposal to assess the environmental effects and identifies opportunities for reducing pol-lution.

radioactive waste: substances discarded from nuclear power plants, medical and scientificprocesses, or weapons manufacture that radiate energy from the disintegration of atomic parti-cles.

resistance: (biological) an organism’s ability to avoid damage from chemicals or disease thatcauses harm in similar organisms. Resistance can spread through a population over severalgenerations.

reforestation: the planting of seeds or seedlings to replace trees.

renewable natural resource: natural products, often living organisms, that can be replaced bynatural processes or reproduction.

sink: a term that describes the destination of a pollutant.

slash and burn: the practice of cutting and setting fire to forest vegetation to clear land forcrops or grazing.

soil erosion: transport of soil particles from a particular place by wind or water, often accelerat-ed by human activities.

source: the point of release of a pollutant.

stratosphere: the layer the atmosphere approximately 16 to 47 km above the Earth’s surface.The stratosphere contains the ozone layer.

sustainable method: a procedure that does not deteriorate the biosphere’s living and nonlivingcomponents.

synthetic chemical: a human-made chemical that is naturally absent or present at low levels inthe environment.

temperature inversion: a weather phenomenon in which an overlying layer of warm air trapscooler air and pollutants near the ground.

thermal release: the discharge of heated water or air from industrial processes.

trophic level: a grouping of organisms that eat the same general type of food. Trophic levelsrise from primary producers, such as plants that make their own food, to consumers, whichCopyright 1999 CyberEd ™ Inc. 38

must consume other organisms as food.

tropical rain forest: an ecosystem located near the equator where temperatures are warm, day-light lasts 11-12 hours per day throughout the year, and rainfall exceeds 250 cm per year.

troposphere: the layer of the atmosphere from the Earth’s surface to about 16 km above the sur-face. This layer is important for influencing weather and is the most affected by human activi-ties.

ultraviolet (UV) light or radiation: light waves similar to visible light but with shorter andmore energetic wavelengths. Excessive exposure to UV light can cause severe damage to bio-logical tissues.

upwelling: the rise of nutrient-rich bottom waters to the surface of the ocean, usually caused byprevailing winds creating water currents near steep coastal areas.

urbanization: the transformation of a rural area to a city-like environment.

urban sprawl: the growth of cities over large areas, usually caused by insufficient planning,growing populations, and reliance on the automobile for transportation.

water-borne pathogen: viruses, bacteria, and other microorganisms found in water that causedisease.

wetlands: an area that supports vegetation and animals well-adapted to regular flooding.


human impacts on the environment program supplement

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